The present invention relates to a method of aiding picture editing using a computer, and more particularly to a method suitable for forming a three-dimensional picture seen from a free visual point based on a two-dimensional picture.
Conventionally, there has been a texture mapping method utilizing perspective projection as an example of forming a three-dimensional picture using a method of composing pictures of a perspective view. The method will be explained more specifically with reference to FIG. 10. The three-dimensional space is regarded as a hexahedron, and a case that a visual point exists within the hexahedron is taken as an example. A three-dimensional model composed of five faces ("a" to "e") at an angle reflected in the field of view is prepared (1000 in FIG. 10). Two-dimensional front pictures corresponding to the faces "a" to "e", respectively, are prepared, and the pictures are stuck to the faces by the texture mapping method. Then, when the faces "a" to "e" are recomposed and a three-dimensional model is restored, desired three-dimensional computer graphics are completed.
This method is realized by means of some three-dimensional computer graphics software, and is discussed in the Design Compilation CG Standard Text Book Committee of Design Compilation-CG Standard Text Book, CG-Arts Society, Japan (1996), pp. 88 to 90.
Besides, the perspective projection is draftsmanship of drawing a three-dimensional configuration on a two-dimensional plane while expressing a feeling of distance by setting a vanishing point and drawing a figure based on this vanishing point. When a picture is drawn on a two-dimensional plane in the field of computer graphics, the perspective projection described above is also used in order to express a feeling of distance in the drawn picture.
In the method of composing pictures of a perspective view by the texture mapping method described above, it has been most desirable that texture pictures to be stuck on the face are photographed or drawn from the front. However, there are cases where it is difficult to obtain a picture seen from the front. For example, when the faces "a" to "e" of the front picture in FIG. 10 is obtained by photographing with a camera, the distances between the planes of the surfaces of the wall, the floor and the ceiling and the camera are different. Thus, it is difficult to take photographs of faces in a wide range from the front.
Further, because of the restriction in the amount of memory contained in the computer, the resolution of the texture picture being taken is low, and it is difficult to raise the resolution of the recomposed perspective view.